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==Material== | ==Material== | ||
1. SYMBIOGENESIS | |||
By Heather Scoville | |||
(Updated on November 24, 2019) | |||
Symbiogenesis is a term in evolution that relates to the cooperation between species in order to increase their survival. | |||
https://www.thoughtco.com/what-is-symbiogenesis-1224708 | |||
2. ENDOSYMBIOTIC THEORY | |||
The endosymbiotic theory, which holds that eukaryotic mitochondria and plastids arose from the engulfment and integration of a bacterium by another cell, has long been a matter of controversial debate, but growing evidence over time has led to the substantiation and universal acceptance of the theory. Recent genetic and biochemical analyses have provided detailed insights into the fundamental events that happened more than a billion years ago. | |||
In 1905, Konstantin Mereschkowsky, a prominent Russian biologist, published his piece of work in “The nature and origins of chromatophores in the plant kingdom” where he proposed that the photosynthetic organelles of plants (plastids, chromatophores) originate from unicellular algae that live in a symbiotic relationship with their host cells. | |||
Plastids are symbionts rather than cell organelles | |||
Mereschkowsky was a leading lichenologist and his theory was inspired by his work on lichens where he had shown that lichens are symbiotic organisms composed of fungi and algae. Four years later in 1909, Mereschkowsky presented his theory of symbiogenesis according to which higher, i.e. more complex cells evolve from the symbiotic relationship between less complex ones. He came up with some astonishing conclusions: "Chlorophyll bodies (i.e. plastids) can grow and divide independently of the nucleus, and produce substances synthetically; in short they do not behave like organs at all, but like independent organisms and must therefore either be regarded as such or as symbionts." | |||
https://www.biooekonomie-bw.de/en/articles/news/symbiogenesis-of-mitochondria-and-plastids | |||
-wird fortgesetzt | |||
==Studierende== | ==Studierende== | ||